Zhiyu Shao Hanxu Sun Qingxuan Jia Ping Ye Yuesheng Tan Development of a General 2-DOF Space Module. 1002-1007 2006 IROS http://dx.doi.org/10.1109/IROS.2006.281782 conf/iros/2006 db/conf/iros/iros2006.html#ShaoSJYT06